-p Apparently there's some kind of misconception from some saying guessing and checking on actual songs is better. Training interval identification in a coordinated way lets you get this ability infinitely faster. Associating intervals will be slower than guess and check only in the beginning. If you want long term improvement ear training is the way to go. Picking out a song by ear by guessing repeatedly is not the same thing as playing a melody out with little or no mistakes in real-time.

-p Finally, whistling or singing to replicate a note correctly is not perfect pitch.